The Lincoln Cosmopolitan front and rear turn signal bulbs both utilize a 1154 size bulb for proper operation. The replacement chart covers 1950 through 1954 production years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Lincoln Cosmopolitan uses the 1154 bulb for both front and rear turn signals across all listed model years, 1950-1954.
The 1154 is a dual-filament bulb, meaning it contains two separate filaments within a single envelope, allowing it to serve more than one lighting function.
It is built on a BAY15d bayonet base, a two-pin offset base design where the two pins are positioned at different heights to ensure correct orientation during installation.
The 1154 carries ANSI standardization applicable in both the United States and Canada.
The 1154 is noted as an older variant of the 1157, a bulb that shares the same dual-filament, BAY15d configuration but became the more widely adopted successor in later automotive applications.
The 1154 is rated for both 6V and 12V electrical systems, reflecting the transitional period in automotive engineering during the early 1950s when manufacturers were shifting from 6-volt to 12-volt systems.
Because the 1154 and 1157 share the same base type and general configuration, substitution between the two warrants caution, as wattage and filament output values differ between the two bulb types.